Technical support knowledge for Application Integration Middleware including WebSphere, CICS, BPM, MQ, Broker, IIB, ODM, DataPower, Mobile, Appliances, and more! Following the IBM Social Computing Guidelines - Steve Webb, William Wentworth, Joseph Lam
A wealth of valuable JVM diagnostic data can be gathered by doing the following tasks:
Generate a Java™ thread dump.
Enable logging of verbose garbage collection data for Server.
Generate a Java heap dump.
Generate a system core dump & snap trc file.
In the overall process of problem determination, diagnostic data must be collected or generated, and the data must be analyzed. Various tools are available to help you analyze diagnostic data for solving problems. Below... [More]
Starting with IBM WebSphere Application Server (WAS) v220.127.116.11, you can install Java 7.0 as an optional feature. WAS v18.104.22.168 comes with Java 6 as the default Java SDK. Java 7.0 can be added at any point in time to the installation, thereby adding the Java 7.0 SDK selection to the possible choices of Java SDKs that can be used. For completeness:
Java 7.0 was shipped as an optional feature that can be installed with WAS v22.214.171.124
Java 7.1 is shipped with WAS v126.96.36.199 (in a full... [More]
Where do I start with sizing the heap for my WebSphere Application Server? This question is very common when trying to determine where to begin sizing your heap for your application when using WebSphere Application Server. The default heap sizes are for use during installation and are often way too small for use in production environments. The first place to begin is to know if the server has 32-bit or 64-bit architecture and whether your installation of WebSphere Application Server is a 32-bit or 64-bit environment. Next determine... [More]
I'll preface this post with two facts: 1. I'm an IBMer and I am not impartial to WebSphere and IBM Java tm , and 2. my primary job function involves solving (sometimes extraordinary) customer problems. That aside, what I wanted to discuss in this post is a comparison between the serviceability capabilities of the IBM JDK and what we'll call: "the other guys". "The other guys" will suffice for a description of any non-IBM Java SDK for the purposes of this post. This post will not be an all inclusive resource for the... [More]
I talked with a WebSphere Application Server support analyst the other day and they mentioned they had seen some "easy problems" coming in to Level 2 support recently. I thought it would be good to blog about these easy ones so you can solve on your own without consuming your time contacting support and sending documentation. Looking at documentation, such as a javacore, can sound like a daunting task if you do not know what to look for. But a javacore is just a readable text file with snapshot information of a running JVM. It... [More]
If there is still free memory in the system when a native out-of-memory error occurs, then the problem is likely to be a shortage of memory in the low-memory region (under 4GB). Although the Java heap can be located above this boundary, other data, which are associated with Java objects, are located in the lower memory segments. Specifically these are the memory segments associated with threads, classes and monitors.
See the following related content:
It has been a while since I wrote about what is hot in the WebSphere MQ (WMQ) support world and there have been quite a few new and helpful documents or articles that have been written or updated since the last time I wrote about what was hot. In case you did not read the previous blogs that I wrote on this topic here are links to the first 2 blog articles because the items in those articles are still relevant today. Many of those items are timeless. They cover topics that someone, somewhere in the world is going to be dealing with... [More]
When it comes to making the decision on when to upgrade the maintenance on a WebSphere MQ system, many people prefer not to think about it. They wait until they are forced to make the upgrade, either because they hit some very serious problems or because a version of MQ has gone unsupported. After going through a "forced" upgrade, it is very common for a person to look back at their experience and wish they could have avoided that scenario. Often times, the person will say "I wish I knew then what I know now". Thinking... [More]
The WebSphere Support Technical Exchange (WSTE) program is a great way for you to learn about popular support topics and questions that come into the IBM support center. Hosted virtually over conference calls and web conferences, the WSTE team organizes a number of technical sessions each month on a variety of products: WebSphere Application Server, WebSphere MQ, WebSphere Business Monitor, IBM Integration Designer, IBM Business Process Manager, CICS Transaction Server, just to name a few. There’s also a chance at the end of each session for... [More]
A WebSphere MQ queue manager and a Java tm or JMS application need to use the same code pages in order for them to talk to each other. If the queue manager is using a code page that the Java environment does not support, then they are basically speaking different languages and will not understand each other. The queue manager uses a property called Coded Character Set Identifier (CCSID). The CCSID is the code page the queue manager uses to encode String data that is returned to an application. For example, if an application makes an MQINQ... [More]
The inspiration for this post comes from a post by ThirdInstance I ran across on the WebSphere Application Server forum on developerWorks . If you use WebSphere Application Server (WAS) and WebSphere MQ (WMQ) together and you're seeing UnsatisfiedLinkError exceptions then keep reading! The cause of an java.lang.UnsatisfiedLinkError , with respect to WMQ interactions, stems from a condition in which a native-language method definition (that is, a method declared with the native modifier in the Java code) is encountered but the JVM cannot locate... [More]
Have you given the IBM Extensions for Memory Analyzer Tool (IEMA) a try? The IEMA project was created by IBM to be a collection of plug-ins for the IBM Monitoring and Diagnostic Tools for Java - Memory Analyzer available in the IBM Support Assistant workbench. The main idea behind this project was to provide some better support for individuals needing to diagnose problems with their IBM software that runs on the Java tm runtime platform. The collection of included plug-ins provides deep insight into your Java-based products like: WebSphere... [More]
Co-authored by: Shawfu Chen and Steve Dittmar
As of IBM WebSphere Application Server V8.5, users on most platforms can choose to run on Java SDK 6.1 or 7.0, with support for 7.1 having been added more recently. Java SDK 6.1 continues to be shipped with, and updated automatically by, the WebSphere Application Server fix packs. However, some users do not realize that Java SDK 7.x fix packs are not included in the WebSphere Application Server fix packs and thus is not automatically installed or kept up-to-date by the... [More]
In one of Vish's blogs, he explains how to install the optional Java 7.x on WebSphere Application Sever 8.5:
Installing optional Java 7.x on WebSphere Application Server 8.5
Once it is installed, however how can you tell which version of Java is actually being used? You can look at the SystemOut.log header, but the output may be a little... [More]
The WebSphere L2 Support team handles its fair share of WebSphere Application Server performance analysis. Often it appears as though the Monitoring Agent (that thing that reports whether the system is behaving - or not) is the problem itself. The truth is, the more problems that the agent has to report, the more noise the agent is going to interject into the diagnostic data. It's a vicious cycle.
One of the common agents that are encountered is Wily. Like any performance monitoring tool, Wily can introduce a... [More]